From 052d1453544511c72674c20b47723e401fd0f8f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miro=20Hron=C4=8Dok?= <miro@hroncok.cz>
Date: Mon, 13 Nov 2023 09:45:05 +0100
Subject: [PATCH] XFAIL TestLocalPath.test_make_numbered_dir_multiprocess_safe
The tested py.path.local.make_numbered_dir function is *not*
multiprocess safe, because is uses os.listdir which itself is not.
The os.listdir documentation explicitly states that:
> If a file is removed from or added to the directory during the call
> of this function, whether a name for that file be included is unspecified.
This can lead to a race when:
1. process A attempts to create directory N
2. the creation fails, as another process already created it in the meantime
3. process A calls listdir to determine a more recent maxnum
4. processes B+ repeatedly create newer directories and they delete directory N
5. process A doesn't have directory N or any newer directory in listdir result
6. process A attempts to create directory N again and raises
For details, see https://github.com/pytest-dev/pytest/issues/11603#issuecomment-1805708144
and bellow.
Additionally, the test itself has a race in batch_make_numbered_dirs.
When this functions attempts to write to repro-N/foo,
repro-N may have already been removed by another process.
For details, see https://github.com/pytest-dev/pytest/issues/11603#issuecomment-1804714313
and bellow.
---
The tested py.path.local.make_numbered_dir function is not used in pytest.
There is a different implementation in _pytest.pathlib.
We plan to remove this module eventually anyway.
Closes https://github.com/pytest-dev/pytest/issues/11603
---
testing/_py/test_local.py | 3 +++
1 file changed, 3 insertions(+)
diff --git a/testing/_py/test_local.py b/testing/_py/test_local.py
index aebee380cb..77a9838cf1 100644
--- a/testing/_py/test_local.py
+++ b/testing/_py/test_local.py
@@ -868,6 +868,9 @@ def test_fspath_protocol_other_class(self, fake_fspath_obj):
py_path.strpath, str_path
)
+ @pytest.mark.xfail(
+ reason="#11603", raises=(error.EEXIST, error.ENOENT), strict=False
+ )
def test_make_numbered_dir_multiprocess_safe(self, tmpdir):
# https://github.com/pytest-dev/py/issues/30
with multiprocessing.Pool() as pool: